Single-phase motor capable of being repeatedly started

Abstract

According to the technical scheme, the single-phase motor comprises a motor body, the motor body comprises a main winding and an auxiliary winding, an electronic centrifugal switch is installed on the motor body, and the electronic centrifugal switch comprises a rectification power supply, a single-chip microcomputer module, a sampling module and a silicon controlled rectifier. The rectification power supply is used for supplying power to the single-chip microcomputer module. The sampling module comprises a first sampling module and a second sampling module, the first sampling module is used for sampling main winding data and transmitting the main winding data to the single chip microcomputer module, and the second sampling module is used for sampling secondary winding data and transmitting the secondary winding data to the single chip microcomputer module; the silicon controlled rectifier is connected with a starting capacitor and connected to the secondary winding in series. The single-chip microcomputer module controls on-off of the silicon controlled rectifier. When the real-time rotating speed of the motor is lower than 70% or 80% of the rated rotating speed, the silicon controlled rectifier is conducted. The circuit has a repeated starting function, can work under the condition of wide voltage of 130-240 V, and is good in use reliability and low in failure rate.

Description

TECHNICAL FIELD

[0001] The utility model relates to single -phase motor technical field more specifically, it relates to a single -phase motor of repeated start -up. BACKGROUND

[0002] Single -phase asynchronous motor is popular in the market because of not being restricted by three -phase power. Usually, the motor designs electromagnetic parameter according to normal power supply voltage standard to ensure that it can have sufficient torque in the interval of voltage wave ±10%. With agricultural mechanization, the number of agricultural single -phase motor is increasing. When using in the field environment, it often needs to be equipped with hundreds of meters of cable, which can easily cause the power voltage to be low, and then cause the motor operating characteristics to be poor, and even unable to operate normally. Although there are solutions such as patent number CN201510160084 dual voltage motor, but under low voltage conditions, it starts slowly, and the mechanical centrifugal switch frequently appears long time arc phenomenon when the contact is disconnected, which makes the motor failure rate high. In addition, the load changes greatly in rural application scenarios, and overload often occurs, which causes the motor speed to drop sharply. At this time, the motor needs to be restarted, and the traditional mechanical centrifugal switch is difficult to meet the demand in performance. The mechanical centrifugal switch is prone to sticky state when the load changes greatly and the speed is unstable, so it is urgent to replace it with a new electronic switch. However, the electronic centrifugal switch on the current market generally lacks the function of repeated start -up. SUMMARY

[0003] In view of the deficiencies in the prior art, the utility model provides a single -phase motor of repeated start -up, which has the function of repeated start -up, can work under the condition of wide voltage of 130-240V, has good use reliability and low failure rate.

[0004] To achieve the above object, the utility model provides the following technical scheme: a single -phase motor of repeated start -up, including motor body, the motor body includes main winding and auxiliary winding, the motor body is installed with electronic centrifugal switch, the electronic centrifugal switch includes rectifier power supply, singlechip module, sampling module and thyristor;

[0005] The rectifier power supply is used to power the singlechip module;

[0006] The sampling module includes first sampling module and second sampling module, the first sampling module is used to sample main winding data and transmits to the singlechip module, and the second sampling module is used to sample auxiliary winding data and transmits to the singlechip module;

[0007] The thyristor is connected with start -up capacitor and is connected in series to the auxiliary winding, and the singlechip module controls the on -off of the thyristor;

[0008] When the real-time rotating speed of the motor is lower than 70% or 80% of the rated rotating speed, the thyristor is turned on.

[0009] The electronic centrifugal switch is further provided with a heat sink on the shell.

[0010] The main winding and the auxiliary winding are both arranged in parallel with the external power supply.

[0011] The rectifier power supply is arranged in parallel with the external power supply.

[0012] The auxiliary winding is provided with a reinforcing coil.

[0013] The electronic centrifugal switch is further provided with a heat sink on the shell.

[0014] The motor of the utility model, through setting second sampling module to the data on the auxiliary winding, when judging that the real-time rotating speed of the motor is lower than 70% or 80% of the rated rotating speed, the single-chip microcomputer controls the thyristor to be turned on, and then makes the auxiliary winding access the starting circuit, and the motor is started repeatedly, so as to avoid the motor shutdown caused by unstable voltage, overload and the like when the agricultural machine is working, and ensure the motor working.

[0015] The electronic centrifugal switch on the motor of the utility model, because the thyristor is turned on for a long time when starting slowly under low voltage, and is turned on frequently when the rotating speed is unstable, therefore, the heat sink is arranged to assist the thyristor to radiate heat, and the long-term stable use of the thyristor is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is an internal circuit structure schematic diagram of the motor.

[0017] Figure 2 It is an external structure schematic diagram of the electronic centrifugal switch.

[0018] Reference signs: 1, electronic centrifugal switch; 2, heat sink. DETAILED DESCRIPTION

[0019] The utility model makes further detailed description in combination with the drawings.

[0020] The embodiment discloses a single-phase motor capable of being started repeatedly. Figures 1-2As shown, including motor body, motor body including main winding and secondary winding, motor body is installed with electronic centrifugal switch 1, electronic centrifugal switch 1 includes rectifier power supply, single-chip microcomputer module, sampling module and thyristor;The role of each part is as follows:

[0021] The rectifier power supply is used to power the single-chip microcomputer module.

[0022] The sampling module includes a first sampling module and a second sampling module, the first sampling module is used to sample the main winding data and transmit to the single-chip microcomputer module, and the second sampling module is used to sample the secondary winding data and transmit to the single-chip microcomputer module. In this embodiment, the sampling module samples voltage data, the first sampling module samples the main winding voltage data, which can be used to determine whether the input voltage of the external power supply is stable, and the second sampling module samples the secondary winding voltage data, which can be used to determine the motor speed. When the speed is low, the secondary winding voltage decreases, and when the speed increases, the secondary winding voltage increases, thereby cooperating with the single-chip microcomputer module to determine the motor speed through the voltage data.

[0023] The thyristor is connected with a starting capacitor and connected in series to the secondary winding, and the single-chip microcomputer module controls the on-off of the thyristor. When the thyristor is turned on, the starting capacitor is connected to the secondary winding. When the single-phase motor starts, the single-phase power supply itself generates a pulsating magnetic field, which cannot directly rotate the motor rotor. The starting capacitor is connected in series in the secondary winding, which can change the phase of the secondary winding current, so that the secondary winding current leads the main winding current by a certain angle (ideally close to 90°). In this way, the main winding current and the secondary winding current together can generate a nearly circular rotating magnetic field. This rotating magnetic field can provide sufficient starting torque for the motor rotor to start smoothly.

[0024] The motor real-time speed is obtained through the above-mentioned sampling module. When the motor real-time speed is lower than 70% or 80% of the rated speed, the thyristor is turned on for repeated starting. The advantage of this embodiment is that the second sampling module collects the motor speed in real time, and when the agricultural machinery is under high load or the voltage is too low and the speed is insufficient, the thyristor is used to connect the secondary winding to assist the main winding to rotate, preventing the agricultural machinery from stopping. And through the on-off control of the thyristor, the problem of frequent contact of the mechanical centrifugal switch and the arc, sticking of the contact and other causes of motor failure and damage is avoided, and the failure rate of the motor is reduced.

[0025] Further, since the thyristor of this embodiment generates a large amount of heat under low voltage and high load, a heat sink 2 is provided on the shell of the electronic centrifugal switch 1, one end of the heat sink abuts against the surface of the thyristor, and the other end is located outside the shell. The heat sink is preferably made of a metal material with strong heat conductivity such as copper or aluminum, which assists the thyristor in dissipating heat to ensure its stable and reliable operation.

[0026] Further, the main winding and the auxiliary winding are both arranged in parallel with the external power supply. The electronic centrifugal switch can ensure the motor to work under the wide voltage of 130-240V, and is especially suitable for the outdoor agricultural machine.

[0027] Further, the rectifier power supply is arranged in parallel with the external power supply. The rectifier power supply rectifies the external power supply into the voltage that can be used by the single-chip microcomputer, and supplies power for the single-chip microcomputer.

[0028] Further, the auxiliary winding of the motor is provided with a reinforcing coil. Since the auxiliary winding of the embodiment needs to be connected to the starting circuit frequently to assist the motor to start repeatedly, the reinforcing coil is arranged to strengthen the auxiliary winding, so that the auxiliary winding can bear greater current.

[0029] The working principle of the embodiment is briefly described as follows: Figure 1 When the motor starts, the initial rotating speed is the slowest. After the second sampling module samples, the single-chip microcomputer turns on the thyristor, the auxiliary winding is connected to the starting capacitor, and the single-phase motor is started in cooperation with the main winding. When the rotating speed reaches the rated rotating speed or more than 70 or 80% of the rated rotating speed, the thyristor is turned off, and the auxiliary winding is connected to the running capacitor. At this time, the function of the running capacitor is the same as that in the prior art, which is used to optimize the magnetic field relationship of the main winding and the auxiliary winding, so that the motor can maintain a relatively stable and efficient rotating magnetic field during operation. The embodiment will not be described again. If the external voltage suddenly decreases or the load of the agricultural machine increases, the rotating speed of the motor decreases and is lower than 70 or 80% of the rated rotating speed (which can be adjusted according to actual needs), the thyristor is turned on, the starting capacitor is connected to the auxiliary winding again, the motor is started again, the torque of the motor is increased, and the motor is prevented from stopping, so that the stability during use is improved.

[0030] The above only describes the preferred embodiment of the utility model, and is not used to limit the utility model. Any modification, equivalent replacement, improvement, etc. within the design concept of the utility model should be included in the protection scope of the utility model.

Claims

1. A single phase motor capable of repeated start-up comprising a motor body including a main winding and an auxiliary winding, characterised in that: The motor body is provided with an electronic centrifugal switch, which comprises a rectifier power supply, a single-chip microcomputer module, a sampling module and a thyristor; The rectifier power supply is used for supplying power to the single-chip microcomputer module; The sampling module comprises a first sampling module and a second sampling module, the first sampling module is used for sampling main winding data and transmitting to the single-chip microcomputer module, and the second sampling module is used for sampling auxiliary winding data and transmitting to the single-chip microcomputer module; The thyristor is connected with a starting capacitor and connected in series to the auxiliary winding, and the single-chip microcomputer module controls the on-off of the thyristor. When the real-time rotating speed of the motor is lower than 70% or 80% of the rated rotating speed, the thyristor is turned on.

2. A single-phase motor capable of repeated startings according to claim 1, characterized in that: The shell of the electronic centrifugal switch is provided with a cooling fin, one end of the cooling fin abuts against the surface of the thyristor, and the other end is located outside the shell.

3. A single-phase motor capable of repeated startings according to claim 1, characterized in that: The main winding and the auxiliary winding are both provided in parallel with an external power supply.

4. A single-phase motor capable of repeated startings according to claim 1, characterized in that: The rectifier power supply is provided in parallel with an external power supply.

5. A single-phase motor capable of repeated startings according to claim 1, characterized in that: The auxiliary winding is provided with a reinforcing coil.

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